Restrictor for refrigeration systems



July 22, 1952 B. H. HUGHES 2,604,119

RESTRICTOR FOR REFRIGERATION SYSTEMS Filed May 26, 1950 INVENTOR.

B H. Hum-4&5

"WWW

ATTORNE Y5 Patented July 22, 1952 UNITED nes rmorroa'so u vSY R :REFRZIGERATIGN STEMS Berfiamin n; Hughes, vvmswn--'sa1em,i-z. :0. Application May as, 1950, Serial No.164A53 My invention. relates to a .Iliiid pressure reducing device. v

[An important object of the invention isto provide an adjustable .fluid pressure reducing device or restrictor for refrigeration systems, wherein itis necessary to reduce the pressure of the coolant .between the condenser or high pressure side of the system and the evaporator for low pressure side thereof.

.A further object of the invention "is to (provide a restrictor of the above mentioned character, wherein the restricted passage is'formed .by the coils of .a spring, a casing holding thespring, and a stem passing axially thnough'lthe spring, the spring .being compressed to vary the cross-secltionalarea of the restricted passage.

A further object of the invention is to provide a vres'trictor of the above ,mentionedrcharaeter which .is very easy to adjust, assemble and dismantle.

Other objects and advantages of the invention will be apparent during the course of the following description:

In the accompanying drawings, forming a part of this application, and in which like numerals are employed to designate like parts throughout the same,

Figure '1 is a diagramma'tic'view of a'refri'gerationsystem "including va "restri'ctor embodying 'my invention, I

Figure 2 is .a greatly enlarged 'central'ivertical I '.long'itudinal section through the-restrictor,

Figure 3 is a horizontal "transverse section taken on line 3-3 ofiFi'gure2, and, Figure 4"is a 'fragmentaryperspective view 1 acoil spring embodied in the restricto'r.

.In the drawings'wherefor the'purpose of illus- 'tra'tion is shown a preferred embodiment of my invention, 'thenumeral I'D designates generally a fluid pressureireducing'device or restrictor connected in a refrigeration system embodying the usual compressor ll, condenser or radiator l2 and cooler or "evaporator 13. In' the system, the 'retrlgerant'flowsifrom the compressor to the condenser, as'sh'own, and from 'the'condenser into the 'restrictor [0, 'by way of *9, conduit or tube 14.

, A'fter flowing through the restrictor ll), and having "its pressureredu'oed thereby, the refrigerant "flows through :a conduit or -tub'e' 'l5' to the eva-porater f3.

The'restrietor I'fl comprises -anelongated ey lindrical body or casing ll having a centraYlOngitudinal cylindrical recess 'or here 4'2 terminating (inwardly 'oftone end of the casing to for form- "ing a bottom or shoulder i l -The opposite end '5 Claims. (Cl. 138 43") oi the bore 12" opens into an enlarged counterbore for recess 'l fl'formed centrally in sun-enlarged cylindrical extension or housing 'I 9 integral with .the casing .Ill. The counter-bore I8 and bore 12' are concentric, as shown. The counter-bore-lfl 'Qp'ens through the outer end of the 'head 19 and has its outer portion screw-threaded as shown at 20. A wide fiat annular "shoulder or seat 21 is :provided at :the top or open end of the bore 12' ,by the bottom of the counter-bore i=8 and-sur- "rounding the lo'o're 12', as shown. A-central'reduced screw-threaded =bore or opening 22 is formed in the end 1-6 and is concentric with the here I 2"; N earand inwardly of the opposite ends of the bore I2, the casing 10 is provided with a pair "of longitudinally spaced radial tubular extensions or nipples 2'3 and Z4, integral therewith,

and having inlet'and outlet passages or bores leading into the bore ii-"near its opposite ends. The nipples 23 and 24 are connected with the 1 conduits 1'4 and t5 'respectively'by coupling devices 2ii-of 'any suitable type. I

Mounted within the bore 12' and removable therefrom and. extending for substantially the entire length =ofthe bore 12 is a resilient-spirally wound coil spring 21 iorme'd of wire which is rectangular in cross-section as -shown. One. end

0f the spring 21 engages the bottom .ror shoulder I1 and itsopposite end terminates inwardlyof or below the seat 2!, -:as1at 28. :[he outsidecircumferenc'e-of the springJi-s=.grounded while the spring it compressed, *to provide an accurate :cylindnical form, and-the inside i circumference of the spring :is grounded when ZthBlSpIingTiS at fits zfree 1 length. when the'sspring il is inserted into the bore 12' and the :spring is in its efree state :or undergno compression, the outside clrcumferencerof :;the spring is slig htly smaller than the diameter ot the cylindrical bore 12 'r, providing an annular clearance between the same which maybe 'fromA003 to .005 inch. The inside circumference or =-b'ore 19 :of -the :spring is accurately ground and is Keysliding or liquid tight "fit 'within the-oylindrical bore o'f the spfing"21,- When the spring is free or elongated. 'l he stem or-.-rod 30- e1tends2thr0ugh the entire length of the spring and haslits sinner endrscrewthreaded to engage within the screwthreaded op'ening fl, as shown. -:--Adjacent to 'the outer =end:of -th'e spring, the -=stem orgirod carries an enlarged cylindrical head 3 l -=integral 'rtherewith and slidablyengaging within-th'e bore 42' and its outen'enda'or face 32 'is fiush' with-ithe seat l the gasket 35, and a flat compression'nut 31 is the low end of; this stem has screw-threaded en:

. stem 30is turnedto, place the spring under com .clearance between the outer. circumference of the spring and wall :of the .cylindrical :bore I2. .The inner circumference of the spring will move I ,radially outwardly from, the stem30, and there ;will be aslight clearance between the innerjcir- 2|. The cylindrical head 3! contacts with the adjacent end of the coil spring 21, as shown. A restricted passage 33 is formed by the turns of the coil spring 21, between the periphery of the stem or rod 30 and the bore I2 and this re- 5 stricted passage 33 is in communication with the bores or passages 25. The restricted passage 33 is continuous and uninterrupted throughout the entire length of the spring so that the liquid refrigerant can pass from the conduit 54 to the conduit l5.

Outwardly of the head 3!, there is a stem or rod extension 34 having a fiat 34'. by means of T which the stem or rod 30 may be turned. .The

extension 34 is in effect a continuation of the stem 30. The extension 34 terminates within the counter-bore l8. 7 M

A flat compressible sealing gasket or washer 35 E surrounds the extension 34 within the counterbore 18 and engages the seat 2| and head 3|. A H fiatwasher or disc 36engages the outer side of mounted within the screw-threadedportion'ifi of the counter-bore I3 outwardly of the washer 36 for tightly clamping the gasket 35 against the shoulder 2| and head 3'I. A removable screwthreaded cap or 'plug 38 is provided for theiouter end of the head [9, as shown. I In use, with the parts assembled as shown and described, the liquid refrigerant flows from the condenser l2, through the conduit 14' and nipple 23 into the upperl end of the restricted passage 33 of the restrictor. .The refrigerant passes through the restricted passage 33 and is expanded and is delivered through the "conduit !5 to the evaporator I3 and is returned to theintake side of the compresson and passes from the outlet side of the compressor to the condenser I2. This is the usual cycle of operationoccurringin a refrigerator V. 1 1; When it is desiredto vary the cross sectional' area of the restricted passage 33, to reduce the same, the cap'38 is removedand a tool applied to thesquare 34' and the stem 30 turned. Since gagement within the screw-threaded bore 22, the stem33 moves downwardly, placing ,thespring 20 under compression and shorteningsame 'When a the spring is placed in the bore I2, before it is headi3l contacts withthe upper endof the spring,

but the spring is n'ot compressed. ,When the pression, as stated, the turns of the spring 2l expand radially whichris. permitted by theslight ,cumference of the spring and, the cylindrical stem 30., Sincethe clearance between the outer circumference of the spring 21 and the bore 125 .may be from .003 to .005jof an inch, the clear- .ance between .the inner, circumference; of the spring and ithestem .33 will befrorn .003to .005

of ,aninch, depending upon the degree of compression of the spring. However, thelongitudi-- nal movement of the spring due to compression, is much greater than the: radial movement 4 of the ,turns'of the spring; andthe; clearance between the inner circumference of thespring and a the stem is compensated for by corresponding re,- ;v

.sectional area ,of the. restricted passage 33, the

major portion of liquid refrigerant will pass through the restricted passage 33. It is thus apparent that by turning the stem 30, the spring 28 may be'compressed, and the cross-sectional area 'of the restricted passage 33 varied or decreased. 7 It is tobe understood that the form of the invention herewith shown and described is to be taken as apreferred example of the same and that various changes in the shape, size and arrangements of parts -may be resorted to, without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim: 1 1. A restrictor comprising a casing having a cylindrical bore and an inlet arranged near one end and an outlet arranged near the opposite end, said opposite end having a screw-threaded recess concentric with the bore, a cylindrical "stem of smaller diameter than the bore of the casing and extending longitudinally of the casf ing in concentric relation thereto and having screw-threadedrecess, a head, secured to the stem and arranged within the opposite end of v the bore, and a'coilspring arranged within the casing and surrounding the stem, said spring having its turns formed'rectangularly in crosssection and having 'its'outer and inner circum- Qferen'ces accurately ground, the spring when circumference slightly spaced from the casing to permit'a radial expansion of the turns of the coil spring whenthe spring is'compressed, and packing means" connected with the casingand arranged exteriorily of and adjacent to the head.

"2. A restrictor comprising a casing having a cylindrical bore and an inlet near one end and an outlet near the opposite end, one end of the casing being closed and having a screw-threaded recess concentric with the bore, a housing carriedby the open end of the casing, a cylindrical stern extending longitudinally within the casing and concentr'ic'with'the bore and having one end screw-threaded and engaging within the screw-threaded recess of the casing, ajhead mounted upontheste'm" and arranged within 5 [the bore, the" stemgextendmg outwardly beyond .the head .intofthe 'housing, a longitudinally ex-- tending coil spring mounted within the casing and surrounding the stein andhaving spaced turns which are rectangular in cross-section,

said springhaving an outer cylindrical circum- I ference which is spaced'slightly from the casing when the'spring is free and an inner cylindrical circumference which slidably contacts withthe .qstem when thespring is free, the spring being compressed by turning the stem, packing within the housing' outwardly of the head, and means to compress the packing including a head having screw-threaded engagement within the housing' -f: Y, i

' 3. A restrictor comprising a casing having a cylindricalbore and inlet-and outlet-openings ,leading from the-bore, a stem extending longig. tudinally within the bore of the casing an spaced from the side wall thereof for forming an annular passage in communication withfsaid inlet and outlet openings, a cylindrical coil spring mounted within the annular passage and ,s'u rrounding the stem and having its coils occupying substantially the entire volume of the; annular passage, there being a slight space between the periphery of the spring and said side wall, the coils of the spring being spaced to form a restricted passage between the inlet and outlet openings, and means to compress the springflto vary the cross-sectional area of the restricted passage.

4. A restrictor comprising a casing having a cylindrical bore and inlet and outlet openings leading from the bore, a stem extending longitudinally within the bore of the casing and spaced from the side wall thereof and -formifia a relatively narrow annular passage between the side wall of the casing and the stem which is in communication with the inlet and outlet openings, a coil spring arranged within the annular passage and surrounding the stem and having its coils formed rectangularly in cross-section, the outer circumference of the spring being spaced slightly from the side wall of the casing to permit slight radial expansion of the spring when the same is compressed, the spring'substantially filling the annular passage and'having its coils spaced apart suflieiently to form a 6 restricted passage between the inlet and outlet openings, and adjustable means to vary the length of the spring and the cross-sectional area of said restricted passage.

5. A restrictor comprising a casing having a bore and inlet'and outlet openings leading from the bore. a stem extending longitudinally within the bore of the casing and spaced from the side wall thereof for forming a passage between the stem and side wall and in communication with said inlet and outlet openings, a coil spring vdisposedfwithin said passage and surrounding the stem and having its coils occupying substantially the entire volume of the passage, the coils of the spring being spaced apart to form a restricted passage'between the inlet and outlet openings, and means to compress the spring to varytthe cross-sectional area of the restricted passage.

BENJAMIN H. HUGHES.

REFERENCES CITED UNITED STATES PATENTS Number v Name Date 960,080 Fay et al May 31, 1910 2,451,387 Harvuot Oct. 12, 1948 2,506,152 Hunter May 2, 1950 

